Different models of joining are known to make up this kind of wire mesh trays. The anchorage systems for the successive tray sections using clamps that are installed between every two sections to hold the transversal metal wires together with lugs are well-known. Other systems hold down the base and the walls of two adjacent tray sections by jointly holding the last transversal metal wire with a splint, a screw and the complementary nut. These systems in which devices or accessories that have to be installed by the worker are used require exactness in the assembly of the tray, usually done at the place of installation with the worker standing on a ladder or in an uncomfortable position.
Bearing these problems in mind anchorage systems have been designed for tray sections without additional devices or accessories, with sections that couple with each other. Spanish patent 2279589 is well-known, in which the tray sections have different ends, one of which is narrowed in height and width in comparison to the other, and the larger end has at least two transversal metal wires that are very close to each other, to insert the transversal metal wire of the smaller end between these metal wires in the section of the next tray. The disadvantage of this tray is the work required to make all the folds in the smaller end.
Spanish patent 2355992 also has a narrowing at one of the ends of each tray section, with folds and peaks, which are linked in order to couple with other folds and peaks at the larger tray end. The union with this invention is overlapping and it requires accessories for correct holding.
European patent EP-0571307 describes a union by means of the installation of long splints on the side walls that protrude from the tray section; these splints have a flange on the inside of one of the ends, where the last but one transversal metal wire interlocks with the following tray section. This method of anchorage with the union between the flanges on each splint does not ensure a perfect holding, and so the patent suggests placing an extra device, a holding clip between the tray sections, when they are of a greater length.